1. Field of the Invention
The present invention relates to a liquid delivering apparatus, in particular, such a liquid delivering apparatus in which a piezoelectric element can be driven at a low drive voltage so as to apply a high pressure to a liquid accommodated by a liquid chamber and thereby deliver the liquid from the chamber to a location outside the chamber. The present invention also relates to a method of producing the liquid delivering apparatus.
2. Related Art Statement
There have conventionally been known various sorts of liquid delivering apparatuses each of which delivers a liquid by using a piezoelectric element, for example, a piezoelectric-type ink jet recording head which is employed by an ink jet recording apparatus. An example of a method of producing the conventional piezoelectric-type ink jet recording head is disclosed by Japanese Patent Publication No. 11-34341. The piezoelectric-type ink jet recording head produced by the disclosed method includes a first piezoelectric layer as an elastic sheet; a common electrode printed on an entire surface of the first piezoelectric layer; and a second piezoelectric layer stacked on the common electrode. The two piezoelectric layers and the common electrode sandwiched by the two layers are subjected to vacuum pressing and then firing, so as to provide an integral body. After the second piezoelectric layer is polarized, the integral body and a cavity sheet having a plurality of ink chambers are stacked on each other, such that the first piezoelectric layer as the elastic sheet is adhered to the cavity sheet with an adhesive. Finally, a plurality of individual electrodes each having a strip-like shape are formed, on the second piezoelectric layer, at respective locations aligned with the ink chambers of the cavity sheet. Thus, a piezoelectric actuator is completed. Moreover, a nozzle sheet and a drive circuit are connected to the thus assembled piezoelectric actuator, and the piezoelectric-type ink jet recording head is completed.
When a positive voltage is applied to an arbitrary one of the individual electrodes and a negative voltage is applied to the common electrode, a strip-like portion of the piezoelectric actuator that is aligned with the one individual electrode is deformed, and is curved into a corresponding one of the ink chambers of the cavity sheet. More specifically explained, the strip-like portion of the piezoelectric actuator is shrunk in directions parallel to the major surfaces of the piezoelectric layers but, since the elastic sheet restrains the shrinkage of the strip-like portion, the strip-like portion is curved toward the ink chamber of the cavity sheet. Consequently the ink accommodated by the ink chamber is compressed, and a droplet of the ink is ejected from an ink ejection nozzle communicating with the ink chamber, so that an image is recorded on a recording medium such as a sheet of paper.